(a) Field of the Invention
The present invention is related to an axial compliant means for a scroll machine, and more particularly to one that achieves for both of the first and the second scrolls a better axial sealing effect by having multiple guiding posts provided at where a piston with corresponding multiple guided holes is pushed-sliding straight and pushing both of the scrolls to be axially in touch and sealed with each other.
(b) Description of the Prior Art
As illustrated in FIG. 1 of the accompanying drawings for a sectional view of a conventional scroll machine containing an axial compliant means of the prior art (U.S. Pat. No. 5,277,563), the scroll machine is essentially comprised of a orbiting scroll (A1) revolving around a fixed scroll (A2) to form multiple compression chambers (A3) including a low pressure chamber (A31), a medium pressure chamber (A32) and a high pressure chamber (A33) with working fluid pressure in them increasing gradually and radial-inwardly.
Both of the orbiting scroll (A1) and the fixed scroll (A2) are axially (and radially) engaged to each other to form the compression chambers. Therefore, an axial sealing effect is required between the orbiting scroll (A1) and the fixed scroll (A2) to avoid leakage of working fluid in compression chambers in the process of compression. As illustrated, an annular recess (A51) containing an annular piston (A5) is formed on a frame (A4). A flow passage (A6) connecting one side to the medium pressure chamber (A32) of those compression chambers (A3) defined by both of the scrolls (A1, A2) through the first scroll and connecting the other side to an annular recess (A51) through the body of the frame is provided so as to guide the working fluid in the medium pressure chamber (A32) to the annular recess (A51). The pressure of the working fluid in the medium pressure chamber (A32) is greater than the suction pressure of the machine and not greater than the discharge pressure of the machine so as to create an appropriate force to push the annular piston (A5) to be against the orbiting scroll (A1) and pushing the orbiting scroll (A1) and the fixed scroll (A2) to be axially in touch and sealed with each other.
Whereas the axial sealing of the orbiting scroll (A1) and the fixed scroll (A2) is produced by the annular piston (A5) pushed-sliding and pushing orbiting scroll (A1) to be in touch with the fixed scroll (A2) axially, the sliding slant of the annular piston (A5) directly affects the sealing result formed by both of the orbiting scroll (A1) and the fixed scroll (A2). However, the annular piston (A5) of the prior art tends to slide slantly due to the greater clearance between where it is engaged to the frame (A4) when subject to pressure force exercised by the working fluid, and that compromises the axial sealing result of the orbiting scroll (A1) and the fixed scroll (A2). Reducing the clearance between the annular piston (A5) and the frame (A4) may help straighten the sliding slant of the annular piston (A5), but it requires additional cost to process both of the frame (A4) and the annular piston (A5).